The spiral pattern rotation speed of the Galaxy and the corotation radius with Gaia DR2

Author(s)

Dias, W. S. ^[1] ; Monteiro, H. ^[1] ; Lepine, J. R. D. ^[2] ; Barros, D. A. ^[3]

Affiliation

^[1] Univ Fed Itajuba, Inst Fis & Quim, UNIFEI, Ave BPS 1303 Pinheirinho, BR-37500903 Itajuba, MG - Brazil

^[2] Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, BR-05508090 Sao Paulo, SP - Brazil

^[3] Rua Sessenta & Tres, 125 Rio Doce, BR-53090393 Olinda, PE - Brazil

• Document type: Journal article
• Source: Monthly Notices of the Royal Astronomical Society; v. 486, n. 4, p. 5726-5736, JUL 2019.
• Web of Science Citations: 4

Abstract

In this work we revisit the issue of the rotation speed of the spiral arms and the location of the corotation radius of our Galaxy. This research was performed using homogeneous data set of young open clusters (age < 50 Myr) determined from Gala Data Release 2 (DR2) data. The stellar astrometric membership was determined using, proper motions and parallaxes, taking into account the full covariance matrix. The distance, age, reddening, and metallicity of the clusters were determined by our non-subjective multidimensional global optimization tool to lit theoretical isochrones to Gaia DR2 photometric data. The rotation speed of the arms is obtained from the relation between age and angular distance of the birthplace of the clusters to the present-day position of the arms. Using the clusters belonging to the Sagittarius Carina, Local, and Perseus arms, and adopting the Galactic parameters Rn = 8.3 kpc and Vo = 240 km we determine a pattern speed of 28.2 + 2.1 kin s-I kpc-I, with no difference between the arms, This implies that the corotation radius is R, = 8,51 0,64 kpc, close to the solar Galactic orbit (Re/R0 = 1,02 + 0.07), (AU)

• FAPESP's process: 13/01115-6 - A study of the galactic structure by means of open clusters
• Grantee: Jacques Raymond Daniel Lépine
• Support Opportunities: Research Grants - Visiting Researcher Grant - Brazil